/// <summary>
/// Creates and connects all nodes in the grid
/// </summary>
private void BuildGrid(Sim.Environment.Terrain terrain)
{
// create the nodes at their proper locations
nodes = new Node[width * length];
for (int z = 0; z < length; z++)
{
for (int x = 0; x < width; x++)
{
int i = x + z * width;
float y = terrain.CalculateHeight(x * spacing, z * spacing);
nodes[i] = new Node(new Vector3(x * spacing, y, z * spacing));
if (y < 5) // underwater
nodes[i].State = NodeState.Invalid;
else if (GMath.AngleOfIncline(terrain.CalculateSurfaceNormal(x * spacing, z * spacing)) < 50)
nodes[i].State = NodeState.Invalid;
}
}
// connect adjacent nodes
for (int z = 0; z < length; z++)
{
for (int x = 0; x < width; x++)
{
Node n = nodes[x + z * width];
// adjacent nodes exist in all 8 directions if the current node is part of the
// interior of the grid; if the node is on an edge, certain spots are empty
bool addN = z > 0;
bool addS = z < length - 1;
bool addW = x > 0;
bool addE = x < width - 1;
if (addN)
{
n.AdjacentNodes.Add(nodes[x + (z - 1) * width]); // N
if (addE) n.AdjacentNodes.Add(nodes[(x + 1) + (z - 1) * width]); // NE
if (addW) n.AdjacentNodes.Add(nodes[(x - 1) + (z - 1) * width]); // NW
}
if (addS)
{
n.AdjacentNodes.Add(nodes[x + (z + 1) * width]); // S
if (addE) n.AdjacentNodes.Add(nodes[(x + 1) + (z + 1) * width]); // SE
if (addW) n.AdjacentNodes.Add(nodes[(x - 1) + (z + 1) * width]); // SW
}
if (addE) n.AdjacentNodes.Add(nodes[(x + 1) + z * width]); // E
if (addW) n.AdjacentNodes.Add(nodes[(x - 1) + z * width]); // W
}
}
}
public static void SurfaceNormal(GraphicsDevice g, Vector3 position, Sim.Environment.Terrain t)
{
BasicEffect e = Shaders.Primitive;
g.VertexDeclaration = new VertexDeclaration(g, VertexPositionColor.VertexElements);
VertexPositionColor[] nVerts = new VertexPositionColor[] {
new VertexPositionColor(position, Color.Red),
new VertexPositionColor(position + t.CalculateSurfaceNormal(position.X,position.Z)*20,Color.Yellow)};
e.Begin();
e.CurrentTechnique.Passes[0].Begin();
g.DrawUserPrimitives(PrimitiveType.LineList, nVerts, 0, 1);
e.CurrentTechnique.Passes[0].End();
e.End();
}
public void Update(Sim.Environment.Terrain t, List<PhysicsBall> pballs)
{
float floorHeight = t.CalculateHeight(position.X, position.Z) + radius;
bool aboveTerrain = position.Y > floorHeight;
if (aboveTerrain && !rising && !falling)
{
if (position.Y - floorHeight > 0.5f) // angle is great enough to slip
falling = true;
else
position.Y = floorHeight;
}
if (position.Y < floorHeight)
position.Y = floorHeight;
if (falling)
{
diffuseColor = new Vector3(1, 1, 0);
info = "Behavior: Falling";
waitingToJump = false;
waitToJumpTimer = 0;
Velocity.Y -= gravity;
if (position.Y <= floorHeight)
{
Velocity.Y *= -bounceFriction; // friction takes away some of the energy
if (Velocity.Y > 0.09f)
{
rising = true;
Vector3 bounceV = t.CalculateSurfaceNormal(position.X, position.Z) * bounceFriction;
Velocity.X += bounceV.X;
Velocity.Z += bounceV.Z;
}
else
Velocity.Y = 0;
falling = false;
}
}
else if (rising)
{
diffuseColor = new Vector3(1, 1, 0);
info = "Behavior: Rising";
waitingToJump = false;
waitToJumpTimer = 0;
Velocity.Y -= gravity;
if (Velocity.Y <= 0)
{
rising = false;
falling = true;
}
}
else if (Velocity.X == 0 && Velocity.Z == 0)
{
info = "Behavior: Waiting to jump";
waitingToJump = true;
diffuseColor = new Vector3(1, 0, 0);
}
float xzFriction;
if (aboveTerrain)
xzFriction = 0;
else
xzFriction = slowDown;
if (Velocity.X < 0)
Velocity.X = MathHelper.Clamp(Velocity.X + xzFriction, -maxSpeed, 0);
else if (Velocity.X > 0)
Velocity.X = MathHelper.Clamp(Velocity.X - xzFriction, 0, maxSpeed);
if (Velocity.Z < 0)
Velocity.Z = MathHelper.Clamp(Velocity.Z + xzFriction, -maxSpeed, 0);
else if (Velocity.Z > 0)
Velocity.Z = MathHelper.Clamp(Velocity.Z - xzFriction, 0, maxSpeed);
// should only update if velocity is nonzero
position += Velocity;
Rotation.Z -= Velocity.X / radius;
Rotation.X -= Velocity.Z / radius;
if (waitingToJump)
{
waitToJumpTimer += 16;
if (waitToJumpTimer > 1500)
{
Vector3 tV = target.Position - position;
tV.Normalize();
Velocity += tV * new Random().Next(5);
info = "Behavior: Jumping!";
}
}
if (Updated != null)
Updated(this, EventArgs.Empty);
}
